Concrete forms



Sept 14, 1965 s. G. JOHNSON ETAL 3,206,156

CONCRETE FORMS Filed Oct. 10. 1963 4 Sheets-Sheet 2 Caz Sept. 14, 1965 s. G. JoHNsoN ETAL CONCRETE FORMS Filed Oct. 10, 1963 4 Sheets-Sheet 3 Foefer H QL/W7 Sept. 14, 1965 s, G. JoHNsoN ETAL 3,205,156

CONCRETE FORMS Filed Oct. 10, 1963 4 Sheets-Sheet 4 INVENTOR: 571mm/ G. ./ohwsa/v BY 4in/w? W /urz United States Patent O 3,206,156 CONCRETE FORMS Stanley G. Johnson, 28536 Elmwood, Garden City, Mich.,

and Arthur W. Kurtz, Detroit, Mich.; said Kurtz assignor to said Johnson Filed Oct. 10, 1963, Ser. No. 316,486 6 Claims. (Cl. 249-185) The present invention is a continuation-in-part of our application Serial Number 49,924, filed August 16, 1960 (now abandoned) and our co-pending application Serial Number 152,707, led October 31, 1961, now abandoned, and relates to the same general subject matter, namely improvements in expansible concrete forms of the variety used in the casting of generally hollow items of rectangular configuration, such as septic tanks, burial vaults and the like.

While particular reference has been made to septic tanks and burial vaults, it must be understood that this disclosure is made for the purpose of description, since the principles involved may be used on many other similar type rectangular concrete products.

It has been well established throughout the years that it is advantageous -to cast hollow concrete articles in an inverted position due to the simplified pouring technique which can be employed. The concrete form of the present invention is poured so that the casting is formed in the inverted position. Since the natural force of gravity acts upon the wet concrete to till the form, as well as vibration to which the form is subjected, the pouring is accomplished without the -time consuming necessity of accurately directing the wet concrete between the sidewalls of the forms. The use of vibration also insures the production of a finished casting without holes.

The present invention teaches the use of a two part concrete form, wherein the inner form is collapsible and has side and end members which are pivotally displaceable about a generally at base, while the corners are pivotably securexl to their respective sidewalls. The outer form is of two part construction and is readily expansible in two directions so as to permit quick and easy removal of a partially cured casting. Although the release and removal of the outer expansible form is a relatively simple matter, a great deal of difficulty has been encountered with other methods of manufacture while attempting the release and removal of a finished casting from the inner form. This is due to the generally uniform wall thickness and the lack of draft in each of the forms.

This application is directed to the inner form and it is a primary object of this invention to provide a collapsible inner form construction, which when used with an expansible outer form will form hollow rectangular configuration castings which can be readily released from both inner and outer forms, in spite of the fact that the sidewalls thereof are of uniform thickness and have no draft.

Another object of the present invention is the provision of a concrete form for use in the manufacture of hollow concrete articles wherein the inner form is manually collapsed to release a casting, with but a single actuating means.

Still another object of the invention is the provision of a concrete form in which the sidewalls, ends and corners of the inner form are pivotally mounted, the sidewalls and ends are pivo-tal about the generally fiat base member, while the corners are pivotal about the vertical edges of each of the sidewalls, thereby forming a collapsible inner form which can be quickly and easily removed from the finished casting.

Another object of this invention is the provision of a relatively simple concrete form which can be readily Patented Sept. 14, 1965 fabricated, using modern mass production manufacturing methods.

These and other objects can be accomplished by the provision of a generally rectangular casting device having a collapsible inner form and an expansible outer form, the inner form is of generally symmetrical configuration and pivotally mounted on a substantially fiat base member; said collapsible inner form is positioned in uniform spaced relationship to said expansible outer form; the collapsible inner fo-rm being made from a pair of symmetrically shaped end members and a pair of symmetrically shaped side members, each of said end and side members having a pivotal means secured adjacent to the lower edge thereof which is cooperable with a pivotal means secured t-o the flat base member; said end and side members displaced from each -other a sufficient amount to have a corner member positioned therebetween, said corner members pivotally secured to each of the vertical edges of the side members adjacent said end memers; a generally flat top member positioned on the upper horizontal edges of said side and end members, as well as the four corners; a pair of vertical guide members which are symmetrically positioned, extend from said base member upward a sutlicient amount to engage and partially support the central portion of said flat top member; `a horizontal member slid-ably positioned on said guide members; a plurality of adjustable pivotal links intermediate said slidable horizontal member and said end and side members; an adjustable linkage `secured to each of the corner members; an ac-tuating bar; selective rotation of said actuating bar displacing each of said pivotal linkages between said corners, ends and sides, so as to expand or collapse the inner form assembly.

Other objects of this invention will appear in the following description and appended claims, reference being had to the accompanying drawings forming a part of this specification, wherein like reference characters designate corresponding parts in the several views.

In the drawings:

FIGURE 1 illustrates a plan view of a concrete form which embodies the present invention.

FIGURE 2 is also a plan View of the concrete form shown in FIGURE 1, with the top removed.

FIGURE 3 is an elevational view of the concrete form illustrated in FIGURE 1.

FIGURE 4 is an elevational view similar to that of FIGURE 3, with the outer expansible form broken away.

FIGURE 5 is a cross sectional view taken substantially along the plane 5-5 of FIGURE 2, with the inner form in the closed position.

FIGURE 6 is an elevational view of the present invention with the outer form broken away and with the inner form shown in the inoperative position.

FIGURE 7 is an elevational View of the concrete form with both the outer form and the inner form broken away, with the inner form illustrated in the inoperative or open position.

FIGURE 8 is a cross section of a corner structure, with the outer form shown in plan View.

FIGURE 9 is an elevational view of a concrete form assembly which illustrates a modified outer form.

FIGURE 10 is a cross section taken along the plane 10-10 of FIGURE 9.

Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in Various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

Referring to FIGURE l, this drawing illustrates a plan view of a two part concrete form 10, which embodies the present invention. The complete concrete form assembly is mounted on a flat, generally rectangular frame or base structure 12. The complete concrete form assembly 10 is made up of two major components, an outer expansible form 20 and an inner form 30 which is pivotally collapsible.

The frame or base structure 12 is of generally rectangular contiguration and has four leg members 13 depending downwardly thereform, one leg being located at each of the four corners thereof. The body or central portion of the base 12 is generally open, while the perimeter 14 is similar to a picture frame, with the inner edge thereof being deformed downwardly. This deformed portion identied by numeral 16 provides a sealing lip on the finished concrete casting, on which rests a cast cover member. The outer edge of the base frame 12 is generally at and has a plurality of upwardly extending dowel pins 18 located thereon. Each of the dowel pins 18 is adapted to engage an aligned opening 19 in a ange 26 which extends along the lower edges of the side and end members 32, 34, 36, and 38. The ange 26 substantially circumscribes the outer expansible form and is in generally parallel relationship to the base frame 12. The elevational view in FIGURE 3 best discloses this structure.

The plan View of the present invention illustrated in FIGURE 2 shows the outer form 20 in the operative position. The inner form 30 is also shown in the operative position, while the flat top cover 240 has been removed for purposes of illustrating the mechanism contained within said form. The linkage mechanism is adapted to simultaneously operate the two sides 32 and 34 which are pivoted on the base 12, as well as the two end members 36 and 38 which are also pivoted on the base frame 12. The corner members 40, 42, 44 and 46, which are disposed intermediate the sides and ends are also operated in unison with another linkage which is cooperable with said rst mentioned linkage. It will also be noted that positioned along the center line of the concrete form are two guide posts 48 and 50. These guide posts 48 and 50 are positioned on and secured to a cross member which extends across the base frame 12. Guide post 48 is secured to cross member 52, while guide post 50 is secured to cross member 54. Each of the guide posts 48 and 50 have positioned thereon, a slidable bearing member 56, to which is aixed to a horizontal or longitudinally disposed actuating member. The actuating member is identiiied with numeral 60.

Each end of the horizontal actuating member 60 has aflixed thereto, a pivotal member 68, which in turn is pivotally secured to each of the end members 36 and 38 of the inner form 30. In addition thereto, a plurality of adjustable pivotal members 72 are interposed between the sides of the horizontal actuating member 60 and the pivotal side members 32 and 34. This structure is perhaps best illustrated in FIGURE 2 of the drawings. It will now be readily apparent that as the horizontal actuating member 60 is caused to be moved up and down von the guide posts 48 and 50, the pivotal members 68 on each end of said horizontal actuating member 60 will operate the pivotal ends 36 and 38, while the sides 32 and 34 are operated by the adjustable linkage members 72 which are pivotally secured between the the sides 32 and 34 and the horizontal actuating member 60.

Also, affixed to the cross members 52 and 54 and secured to the base member 12 is a rectangular shaped supporting structure 74 which locates and positions four pivotal L-shaped links 76, 78, 82 anr 84. The upper end portions 96, 98, 102 and 104 of the L-shaped members are secured to a plurality of linkage arms 86, 88, 92 and 94 which in turn are connected to the four pivotal corner members 40, 42, 44 and 46 thereof. Each of the connecting links between the corners, sides and ends are adjustable.

The sides 32 and 34 are of generally rectangular coniiuration. The upper horizontal edges thereof are flanged inwardly, while the lower horizontal edges thereof are positioned in substantial alignment and in parallel relationship to the inner perimeter of the base frame 12. In addition, the lower horizontal edges of the sides 32 and 34 are pivotally secured to the frame structure 12 by a plurality of hinge members 106. The vertical edges on the ends of each of the sides 32 and 34 have pivotally secured thereto, hinge members 108 which position and locate each of the respective pivotal corner members 40, 42, 44 and 46.

The end members 36 and 38 are also of generally rectangular configuration and are flanged inwardly on the top horizontal edges 37 and 39 thereof. The lower horizontal edge of each end member is positioned in alignment and generally parallel relationship to the inner perimeter of the ends of the base frame 12. Hinge 109 is positioned between the base frame 12 and the ends 36 and 38 respectively, thereby making the ends 36 and 38 pivotable about the base frame 12.

The operating means 110 for expanding or collapsing the inner form extends transversely across the bottom of the base frame 12 and is operable to cause the various linkages attached thereto to operate the sides, ends and corners therebetween `so as to extend or collapse the form as desired.

An arm 114 is secured to the actuating means 110, to which are secured the pivotal links 116, 118, and 122. One end of each of the links 116, 118, 120 and 122 is pivotally secured to one of the free ends of the L-shaped links 76, 78, 82 and 84 respectively. The pivotal links 116 and 118 are secured to the ends of links '76 and 78, while links 120 and 122 are secured to the ends of links 82 and 84 respectively. Another link 124 is secured pivotally to bracket 126 at one end land `to arm 114 at the other.

The cover member 240 of the present invention is generally flat and of rectangular configuration with a pair of downwardly depending hollow sleeve members 49 and 51 secured to the central portion thereof. The hollow sleeve members 49 and 51 are adapted to align the top ends of the guide posts 48 and 50, sot as to accurately position the cover member 240 in the proper location with respect to the sides 32 and 34 and the ends 36 and 38 of the inner form.

Operation When the single handle member 112, connected to the operating mechanism through actuating means 110 is rotated in the direction of the arrow, the arm member 114 to which links 116, 118 and 120 and 122 are secured are caused to be moved. In addition, the horizontal member 60 which is movable on the vertical guide posts 48 and 50 is also caused to be displaced to the closed posit1on. lllustrated in FIGURE 5. This results from the motlon transmitted through the pivotal link 124. When this occurs, the rectangular end members 36 and 38 are caused to be moved outwardly to the vertical position, through the actuation of the pivotal members 68 which are plvotally secured to each end of the horizontal member 60. The rectangular sides 32 and 34 are moved outwardly to the vertical position by the action of the llnks 72 interposed between the sides 32 and 34 and horlzontal member 60. As the L-shaped links 76, 78, 82 and 84 are moved, the linkage 86, 88, 92 and 94 pivot the corners 40, 42, 44 and 46 into engagement with the end members 36 and 38. The flat top member 240 1s then placed `in position so that the form is ready for pouring, assuming the outer form 20 is likewise properly posltioned. The casting is poured in an inverted position to facilitates a Simple manufacturing procedure.

l When the pouring is completed, the resulting casting 1s allowed to cure for a short time, after which the inner form 30 is collapsed to permit the removal of the nished casting. The outer expansible form in the closed condition and the casting are then lifted from the base member 12, using the cylindrical members 150 on the outer form 20 as a pivot. After the mold and casting are inverted, the outer form 20 is removed to expose the finished, upright, hollow casting.

The same operation is then repeated in the sequence above outlined as many times as desired to obtain the required number of castings.

Having thus described our invention, We claim:

1. In a concrete form for the manufacture of generally hollow, draft free, castings, the combination of,

a retractable inner form pivotally secured to a fiat base member;

a pair of rectangular end members, each pivotally secured to said flat base member in pre-determined spaced relationship;

a pair of rectangular side members, each pivotally secured to said base member in pre-determined spaced relationship;

four symmetrical right angle corner members pivotally secured to each of the opposed vertical edges of said side members;

a rectangular top member removably positioned on the horizontal edges of said side, end and corner members, the central portion of which is supported on a pair of guide posts which extend from the flat base member;

said guide posts symmetrically positioned and have a slidable horizontal member positioned thereover;

a plurality of adjustable pivotal links interposed intermediate said horizontal member and said side and end members;

an actuating member;

a pivotal link between each of said corner members and said actuating member;

`displacement of said actuating member in 4one direction operating all of said pivotal linkages to expand said inner form, displacement in the opposite direction retracts said inner form.

2. In a concrete form for the manufacture of generally hollow and draft free articles, the combination of,

an expansible inner form having a pair of rectangular side and end members pivotally secured in pre-determined spaced relationship; a hollow base frame structure;

four 90 corner members, one pivotally secured to each of the four corners of the form, one on each of the opposed vertical edges of each side member;

a removable at top positioned on the top horizontal edge of said side, and end corner members;

a pair of round guide members symmetrically positioned and extending vertically upward from a pair of cross members in said base frame;

a horizontal member slidably positioned on said vertical guide members;

a plurality of pivotal links intermediate said side, and

end corner members;

an actuating member, said actuating member adapted to operate said pivotal linkages upon displacement of said horizontal member to which the linkage members are pivotally secured,

3. In a concrete form for the manufacture of hollow, uniform wall thickness articles and having an inner form which is collapsible, the combination of;

a base member;

an inner form with a pair of generally rectangular shaped end members and pivotal means secured to said base member adjacent to the lower horizontal edge portions thereof;

a pair of rectangular shaped side members, each having pivotal means secured adjacent to the lower horizontal edge portions thereof;

four right angle corner members, one pivotally secured to each of the vertical edges of each of said side members;

a substantially flat top removably positioned on the upper horizontal edges of said side, end and right angle corner members;

a horizontal member;

guide members extending from said base member and adapted to guide said horizontal member positioned thereover;

a plurality of pivotal links interposed between said side, end and right angle corner members;

and actuatiing means for the displacement of said pivotal links to expand and retract said inner form.

4. In a concrete mold for use in the manufacture of generally hollow, uniform wall thicknessA and square corner articles, the combination of,

an inner form;

a pair of rectangular shaped end and side members, each of said side and end members having pivotal means secured adjacent the lower edges thereof; a generally at base member;

said pivotal means secured to said generally at base member;

four right angle corner members positioned intermediate said side and end members respectively, one corner member pivotal about each end of said rectangular side members and at right angles to each of said first mentioned pivotal means;

a generally flat top removably positioned to overlie the upper edges of said side, end and corner members;

a single actuating means for pivoting said sides, ends and corners into a pre-determined position;

and means for locating said at top member in alignment with said side end and corner members, the side walls and end walls of said inner form in the closed position being in parallel spaced relationship to each other.

5. In a concrete form for the manufacture of draft free and hollow concrete products which has an inner form that is retractable, the improvement comprising a pair of generally rectangular side members;

a pair of rectangular end members;

a generally flat base member;

said side and end members pivotally secured to said generally at base member in pre-determined spaced relationship;

four right angle corner members disposed between said side and end members and pivotal about the Vertical edges of said side members;

a pair of symmetrically positioned guide members Vertically mounted on said base member;

a flat rectangular top positioned on said side, end, corner and guide members;

a horizontal actuating bar slidably positioned on said guide members in generally parallel relationship to said top member;

a pivotal link intermediate each end of said horizontal actuating bar and each end member;

a pivotal link intermediate each of the sides and the horizontal actuating bar; an actuating member;

a pivotal link secured to each of the corner members and said actuating member;

a pivotal link intermediate said horizontal actuating bar and said actuating member;

displacement of said actuating bar operating said side and end members, While said actuating member operates said horizontal actuating bar and said corner members to expand said inner form, while displacement of said actuating member in another direction will retract said form to permit removal of a finished casting.

6. In a device which has an inner form for the manufacture of generally uniform wall thickness concrete products, the combination wherein,

said inner form is collapsible; a at platform member which forms the base; end members on said inner form which are pivotable about the flat platform base member;

side members which are pivotable about the at platform base member; corner members which are pivotable about the vertical edges of side members; said cornei members disposed in pre-determined spaced relationship between said side and end members; a plurality of adjustable links interposed between said side, end and corner members, which linkages are cooperable with an actuating member to expand and `contract said inner form, dependent on the. direction of movement.

References Cited by the Examiner UNITED STATES PATENTS 2,578,310 12/51 Lager 25--130 2,598,830 6/52 Praeger 25-128 2,827,683 3/58 Benart et al. 25-130 2,828,526 4/58 Blasius et al 25-130 2,903,777 9/ 59 Mitchell 25-130 J. SPENCER OVERHOLSER, Primary Examiner.

ROBERT F. WHITE, MICHAEL V. BRINDISI, WIL- i LIAM I. STEPHENSON, Examiners. 

1. IN A CONCRETE FORM FOR THE MANUFACTURE OF GENERALLY HOLLOW, DRAFT FREE, CASTINGS, THE COMBINATION OF, A RETRACTABLE INNER FORM PIVOTALLY SECURED TO A FLAT BASE MEMBER; A PAIR OF RECTANGULAR END MEMBERS, EACH PIVOTALLY SECURED TO SAID FLAT BASE MEMBER IN PRE-DETERMINED SPACED RELATIONSHIP; A PAIR OF RECTANGULAR SIDE MEMBERS, EACH PIVOTALLY SECURED TO SAID BASE MEMBER IN PRE-DETERMINED SPACED RELATIONSHIP; FOUR SYMMETRICAL RIGHT ANGLE CORNER MEMBERS PIVOTALLY SECURED TO EACH OF THE OPPOSED VERTICAL EDGES OF SAID SIDE MEMBERS; A TECTANGULAR TOP MEMBER REMOVABLY POSITIONED ON THE HORIZONTAL EDGES OF SAID SIDE, END AND CORNER MEMBERS, THE CENTRAL PORTION OF WHICH IS SUPPORTED ON A PAIR OF GUIDE POSTS WHICH EXTEND FROM THE FLAT BASE MEMBER; SAID GUIDE POSTS SYMMETRICALLY POSITIONED AND HAVE A SLIDABLE HORIZONTAL MEMBER POSITIONED THEREOVER; A PLURALITY OF ADJUSTABLE PIVOTAL LINKS INTERPOSED INTERMEDIATE SAID HORIZONTAL MEMBER AND SAID SIDE AND END MEMBERS; AN ACTUATING MEMBER; A PIVOTAL LINK BETWEEN EACH OF SAID CORNER MEMBERS AND SAID ACTUATING MEMBER; DISPLACEMENT OF SAID ACTUATING MEMBER IN ONE DIRECTION OPERATING ALL OF SAID PIVOTAL LINKAGES TO EXPAND SAID INNER FORM, DISPLACEMENT IN THE OPPOSITE DIRECTION RETRACTS SAID INNER FORM. 